1. Field of the Invention
The present invention generally relates to geometrical instruments for measuring distance. More particularly, this invention relates to an improved retractable, tape measure.
2. Description of the Related Art
Retractable tape measures have been popular for many years and have often been the subject of patent grants. For example, see U.S. Pat. Nos. 3,908,277, 4,153,996, 4,194,703, 4,439,927, 4,748,746, 4,938,430, 5,210,956 and 5,983,514.
In general, a retractable tape measure includes some widely recognized features, including: a metal tape that is retractably mounted within a housing, a retraction means for retracting the tape through a housing opening, an end stop for preventing the free end of the tape from retracting into the housing, and a lock which releasably secures the tape in an extended position. In order to provide stiffness to such a tape so that it""s free end can extended to a maximum distance from its housing without bending, the tape is usually manufactured with lateral cross-section curvature created by having the tape""s ends turned upward. This curvature also serves to differentiate the top side of the tape.
All of the above referenced tapes also share some other, not so widely recognized, features which serve to significantly limit their usefulness. These features include all these tapes having: (1) retractable tapes that extend from their housings at a point on the side of the front side of the housings which is proximate the housing""s bottom surfaces, and (2) measurement indicia on only the top surface of the tape.
The reason for these features is apparently that such tapes are primarily intended for use in making measurements on surfaces or in planes that are lower than the eye level of the user, and where there are no obstructions above the plane of a desired measurement which would necessitate a user having to bend the tape downward so as to reposition the top portion of a tape""s housing out of the way of such an obstruction. The logic of this last statement becomes apparent when it is recognized that the turned upward edges of the tape destroys its vertical symmetry, and means that such a tape cannot just be turned over, so as to make the tape""s top surface indicia visible or to reposition the top portion of the housing out of the way of an obstruction, without losing the stiffening and avoidance-to-bending characteristics provided by the tape""s turned upward edges.
Thus, despite their popularity, such standard tape measures are not always easy to use. For example, electricians and others often encounter significant problems in using a standard tape measure when they are making measurements from a wall to a distant spot that is more than an arms length away on an adjoining ceiling. See FIGS. 1-2. The first obstacle encountered is the lack of any markings on the tape""s bottom side. Meanwhile, the numbers on the tape""s top side cannot be seen by its user while he/she is holding the tape up against the ceiling. Unfortunately, as noted above, the tape cannot be turned over or the top portion of the tape""s housing moved away from the ceiling without losing the stiffening effect of the tape""s turned-up edges.
U.S. Pat. No. 1,986,551 discloses a steel, retractable tape which has indicia on the tape""s bottom surface and at least some degree of lateral cross-section curvature. However, the tape""s degree and extent of lateral cross-section curvature is unclear, as is its effectiveness for preventing tape bending. This situation arises because this patent""s use of some imprecise wording and vague drawings at key points in its disclosure. For example, the tape is said to be xe2x80x9ccurved in cross-section and, when unrestricted, will assume a straight or rod-like form, as shown in FIGS. 1 and 2,xe2x80x9d (see col. 2, lines 12-14). However, the effect of the tape""s lateral cross-section curvature in promoting this xe2x80x9cstraight or rod-like formxe2x80x9d is non-existent in FIGS. 1 and 2 since these figures reveal a steel tape with its edges turned downward, which actually promotes bending. While the tapes in FIGS. 1 and 2 show no bending, this is not surprising since any such steel tape as shown in these figures (i.e., 0.5 inch width, a non-negligible thickness, and with its free end only four inches from its housing), would not, regardless of the lateral cross-sectional shape of the tape, be expected to show a degree of bending that is discernible to the naked eye. Meanwhile, the reason given in this patent for the downward turned edges is xe2x80x9cto obtain direct close readings on the object measuredxe2x80x9d (see col. 1, lines 34-35), which suggests that this patent""s tape measure is intended for use in measuring the tops of objects on which the tape has been extended, and therefore would not, in this situation, need support to prevent it from being bent downward under the force of gravity.
Thus, despite this prior art, one finds that standard, tape measures are not very user friendly. The need exists for an improved, retractable tape measure that is easier to use. An object of the present invention is to provide an improved, retractable tape measure that will overcome user problems such as the one described above.
Another object of the present invention is to provide an improved, retractable tape measure that can be used, for measuring extended distances, just as easily when those distances are on a ceiling or a floor.
Other objects and advantages of the present invention will become readily apparent as the invention is better understood by reference to the accompanying drawings and the detailed description that follows.
The present invention is generally directed to satisfying the need set forth above and the problems identified with prior retractable, tape measures.
This present invention is an improved, retractable tape measure. It is an improvement of the standard retractable tape measure which has a housing with an opening through which is extended and retracted a measuring tape which has a top and bottom surface, turned-up edges, a free end and top measurement indicia inscribed on the top surface of the tape. Such a tape is seen to be improved by the inclusion of bottom measurement indicia on the bottom surface of the tape, and locating the housing opening in the front portion and proximate the top portion of the housing so that, when the tape measure is being used to measure against an overhead surface, the portion of the tape that is extending through the opening and in closest proximity to the housing can be held in close proximity to the overhead surface without having to bend the tape to move the housing away from the overhead surface.
These improvements are significant in that they greatly enhance the usefulness of such a tape measure, especially for measuring overhead distances.